基于确定性迁移模型研究聚乙烯食品接触材料中紫外吸收剂的迁移规律

Study of the migration law of UV absorbants in polyethylene food contact materials based on deterministic migration model

目的研究不同条件下低密度聚乙烯(LDPE)食品接触材料中3种紫外吸收剂[2-(2′-羟基-5′-甲基苯基)苯并三唑(UV-71]、2-羟基-4-甲氧基苯并苯酮(UV-9)、2-羟基-4-正辛氧基苯并苯酮(UV-531))的迁移,基于确定性迁移模型得出吸附扩散的重要参数—分配系数和扩散系数,并研究其迁移规律。方法采用双螺杆挤出机将LDPE粉料和3种紫外吸收剂混合并挤出造粒后,在175℃~180℃,70 Pa下,注塑为膜。针对高浓度酒精类食品生产加工储运场景,采用50%、70%、95%乙醇作为食品模拟物,在20℃、40℃、60℃下进行迁移试验。用超高效液相色谱仪测定不同时间点紫外吸收剂的迁移量,根据Piringer模型对数据进行拟合,得出扩散系数和分配系数,研究温度、食品模拟物、紫外吸收剂含量对迁移的影响。结果温度对迁移影响最大,随着温度升高紫外吸收剂扩散系数增加,分配系数降低;乙醇含量对紫外吸收剂的扩散系数影响不显著,而随着乙醇含量的增加分配系数逐渐减小;紫外吸收剂的含量对迁移影响最小,扩散系数和分配系数变化不明显(除UV-71的分配系数随含量的增加而降低)。结论采用Piringer确定性模型研究LDPE中3种紫外吸收剂向高浓度酒精类食品模拟物迁移的扩散系数和分配系数,为食品接触材料中紫外吸收剂的风险评估提供了有效方法。

Objective The migration of three kinds of UV absorbants [2-hydroxy-4-methoxybenzophenone(UV-9), 2-(2-hydroxy-5-methylphenyl)benzotriazole(UV-71) and 2-hydroxy-4-n-octyloxybenzophenone(UV-531)] in low density polyethylene(LDPE) food contact materials under different conditions was studied. Based on the Piringer deterministic migration model, the important parameters — distribution coefficient and diffusion coefficient — of adsorption and diffusion were obtained, and the migration law were studied. Methods LDPE powder and three kinds of UV absorbents were mixed and granulated by twin screw extruder, and the film was formed at 175-180 ℃ and 70 Pa. Simulating processing and storage of high-concentration alcoholic food, 50%, 70% and 95% ethanol were used as food simulations, and the migration tests were carried out under 20, 40 and 60 ℃. Ultra-high performance liquid chromatography(UPLC) was used to determine the migration content of UV absorbents at different time points. The diffusion coefficient and distribution coefficient were obtained by fitting the data with Piringer model. The influence of temperature, food simulants, and target content on migration were studied. Results Temperature had the greatest effect on migration. With the increase of temperature, the diffusion coefficient of UV absorbents increased and the distribution coefficient decreased. The effect of ethanol content in food simulants on the diffusion coefficient of UV absorbent was not significant, but the distribution coefficient decreased with the increase of ethanol content. The content of UV absorbent had the least effect on the migration, and the diffusion coefficient and distribution coefficient had no obviously change(except that the distribution coefficient of UV-71 decreased with the increase of the content). Conclusion The Piringer deterministic model was used to study the diffusion coefficient and distribution coefficient of the migration of three kinds of UV absorbents in LDPE to high concentration alcoholic food simulant, which provided an effective method for the risk assessment of UV absorbents in food contact materials.